This invention relates generally to the field of molecular gas lasers and more particularly to electrode structures for transversely exciting a molecular gas laser.
Carbon dioxide transversely excited atmospheric (TEA) lasers are well known. Such apparatus, for example, is described in a publication entitled "High Peak Power Gas Lasers", by Jacques A Beaulieu, which appeared in the proceedings IEEE, April, 1971, at pages 667-674, inclusive. In general, lasing action is accomplished by initiating a transverse pulsed glow discharge between longitudinally extending electrode structures whereby the desired population inversions are generated in the energy levels of a molecular laser gas contained within the laser cavity to cause laser operation. Furthermore, electrical discharges in conventional flat continuous electrode TEA lasers usually require preionization of the gas volume in order to ensure a uniform discharge. Such techniques typically require ultra violet sources or high voltage triggering circuits. The latter technique, which is most common, necessitates a delicate balance of electrode separation and trigger wire position for the system to operate properly. Pin electrodes have also been used but suffer from the disadvantage of complexity of design and a quasi-uniform or filamentary discharge structure depending upon the particular pin density and geometry. Cylindrical coaxial TEA laser systems are also well known in the art, typical examples of which are disclosed in U.S. Pat. No. 3,828,277, U.S. Pat. No. 3,898,586, and U.S. Pat. No. 3,936,767.
Accordingly, it is an object of the present invention to provide an improved coaxial cylindrical symmetric electrode configuration for a carbon dioxide transversely excited atmospheric laser which allows for better utilization of the active gain region, establishment of a uniform discharge, potentially better mode and beam control, and a simpler and more economical structure which provides reliable arc free operation for a minimum of electrode preparation.